Repeated sprint training improves both anaerobic and aerobic fitness in basketball players

1. Introduction

Basketball is a team sport with intermittent characteristics that elite players perform several high-intensity actions (i.e., sprints and jumps), alternating with low-intensity movements (i.e., walking and jogging) [1]. It might be defined as a sport with a great anaerobic and aerobic component [2]. Moreover, during intense periods of the games, time-motion studies have found that 28.5–46.1% of the actions are sprints, and players often repeated these high-intensity actions every 21–39 s [3, 4]. Thereby, maintaining the maximum performance after several sprints is fundamental. Accordingly, the ability to preserve the best performance over a sequence of sprints, defined as Repeated Sprint Ability (RSA) is characterized by short high-intensity sprints ( 10-s) with short recovery periods ( 60-s) [5]. The RSA is commonly used as a specific test of athletic performance in sports that involve running as the main form of movement [6].

Traditionally, in the pre-season, the main physical components required in sports are emphasized during training, including their physiological determinants [7, 8]. The energy system contribution to RSA is altered according to the number of bouts and recovery periods, that is, a gradual increase in aerobic fitness occurs as more sprints are added in the training [9, 10]. Thus, high aerobic fitness is described as a recovery optimization during high-intensity intermittent exercise, a common trait in high-performance basketball players [2]. Furthermore, the relevance of aerobic fitness in basketball players is observed in studies that show the relationship between aerobic power and RSA [11], game time spent at high-intensity performance during the matches [3], and in high-performance athletes [12]. Thus, strategies that aim to improve the RSA physiological determinants are needed.

Interestingly, previous studies have demonstrated that Repeated Sprint Training (RST), was effective for improving aerobic fitness in young basketball players without negative effects on lower limbs explosive strength [13, 14]. RST is a high-intensity aerobic interval training method that aims at the improvement of neuromuscular (i.e. sprints and jumps) and metabolic function in the short-term period (2–6 weeks) [15, 16]. In fact, it is well established that both movements require a greater neuromuscular demand (i.e. motor unit synchronization, recruitment of high-order motor units, stretch-shortening cycle efficiency, and musculotendinous stiffness) to develop maximal power [17]. Accordingly, previous studies have reported a relationship between vertical jump height and the maximum speed achieved at a 30-m distance, indicating that the relationship is attributed to the similar demands of stretch-shortening cycle required in both movements [18, 19]. Thus, RST might be an interesting strategy to include in training during the pre-season to improve muscle power performance in basketball players.

A meta-analysis conducted by Taylor et al. [16] demonstrated that RST enhanced RSA, high-intensity running, and countermovement jump (CMJ) performances. Although this meta-analysis [6] provided interesting data regarding the improvement of several fitness components related to sports performance following RST, some limitation could be pointed out in this study, which in turn, reinforce the need of futures investigations on this topic. First, only 13 studies were included in the final analysis while the authors found a low to moderate heterogeneity of the studies mostly because of the small sample size, which may have affected both the magnitude and the uncertainty of these effects [20]. Second, both controlled and non-controlled trials were included in the analysis. For instance, only two controlled trials investigated the effect of repeated-sprint training on vertical jump performance and only three on sprint performance. Considering that during the pre-season several fitness components are targeted to be improved, studies that add non-controlled trials design make it difficult to isolate the effects of RST. Thereby, any improvement in fitness components should be considered with caution because it is still unknown if those changes occur as a result of technical-tactical training routine. Some studies have demonstrated improvements in skills and physical performance following game-based training (i.e. technical-tactical training routine) [21, 22, 23]. Thus, to fully quantify and understand the effects of repeated-sprint training on the athletic group, a controlled randomized trial design is necessary. Additionally, due to the high frequency of jumps during games and training sessions in basketball [3, 4], improvements in a single effort jump performance may not reflect the real game demand in sports with intermittent nature. For instance, during a basketball game, an athlete might perform ∼ 44 jump actions [3].

Thus, it is important to identify strategies to improve the ability to maintain jump power throughout matches, which is crucial for high performance. However, data regarding the short-term effect of RST on repeated vertical jump ability (RVJA) in basketball players are still unavailable. Thus, the aim of this study was to analyze the effect of 4 weeks of RST on the anaerobic and aerobic fitness of basketball players during pre-season. Our hypothesis was that RST strategy might improve the RSA, vertical jump, and aerobic fitness in comparison to the traditional basketball technique training.

2. Methods

Table 1 reports the relative changes resulting from the intragroup analysis, after the RST sessions, for the RSA and RVJA indices and aerobic fitness.

4. Discussion

The present study demonstrated that the RST improved athletic performance compared to the common technique of pre-season training in basketball players. RST was “likely” and “almost certainly” more effective in improving the RSA B , RSA W , RSA DEC , CMJ, and V max . In addition, practical significance analyses suggested that RSA AT , RSA TT , VO 2 ⁢ max , RVJA 15 , and RVJA 60 were “likely” to “very likely” beneficial for the RST. These data add to the current body of knowledge and confirm the hypothesis that RST provides stimuli for improving the CMJ height, sprint speed, and the ability of active muscles to preserve speed decrement and maintain short-duration supra-maximal exercise.

The effectiveness of RST is an interesting finding within the team-sport context, specifically because it confirms the improvements in actions frequently required to players during the games (sprints and jumps) [2, 3]. Those improvements are supported by a recent meta-analysis that demonstrated RST is effective on power, speed, RSA, and endurance in diverse athletic groups [16]. RSA and vertical jump are important components of high-intensity performance in team sports, including variables as acceleration/deceleration, player ability to repeatedly produce maximal sprint efforts and explosive strength capacity that are fundamental parameters in competitive basketball games [2]. The results of the present study are in agreement with those previous investigations reporting similar training type designed for young basketball [13], soccer [35], and adult handball [36] players, which had reported improvement on RSA and jumping performance.

Noteworthy, this is the first study to investigate the effect of RST on repeated vertical jump performance. Despite non-significance on RVJA indices, practical analyses suggested that RST provides stimuli from “likely” to “very likely” for improving RVJA 15 and RVJA 60 , respectively. The mechanisms underlying the improvement in RSA B , RSA W , and CMJ height during RST may be a consequence of increased leg muscle explosive power, improvements in motor unit synchronization, and stretch-shortening cycle efficiency [37]. As previously reported, a strong correlation is reported between CMJ and 30-m sprint time performance in basketball players [18, 19]. This is not a surprise, since both CMJ and sprints movements, especially when the player reaches the maximum speed, present characteristics of the stretch-shortening cycle [38] as well as greater leg muscle explosive power. Another possible explanation for the improved performance on RSA indices after RST may be related to the usual learning effect of training exercise specificity between this exercise and RSA [39].

Basketball players perform 55–105 sprints movements during a game, which can be repeated every 21–39 s [3, 4]. Those time-motion studies reinforce the practical relevance of “almost certainly” beneficial change ( ∼ 53%) observed in the sprint performance decrement after RST, which is supported by a similar response in young sub-elite male soccer players after five weeks of RST [35]. In the present study, physiological measurements were not obtained, but previous studies demonstrated effects of RST on sarcoplasmic reticulum Ca 2 + release [40], autonomic function [41], and muscle oxygen uptake kinetics [42], which affect repeated sprint performance. Moreover, it should be noted that studies involving elite adult players [23, 24] frequently failed to find positive responses to RST. Therefore, the improvement in sprint performance found in our study may be related to the competitive level of players (college vs elite adult players).

Aerobic fitness parameters are also considered a key component of physical fitness in basketball players [2]. Changes in VO 2 ⁢ max and V max were “likely” to “very likely” beneficial following RST, respectively. Both components are considered crucial for basketball players due to the fact that aerobic fitness is related to the player’s capacity to cope with external training load during daily training sessions [43]; also, it was positively related with time spent at high intensity during games in Under-19 basketball players [3]. Thereby, previous studies have found a higher percentage of change ( δ %) in aerobic power following RST with change of direction (180 ∘ ) when compared to the results of the present study [24, 44]. In addition, Buchheit et al. [8] found greater cardiorespiratory demand in repeated sprints with direction change (180 ∘ ) when comparing to sprints without it, which may explain those differences. It should be noted that RST is a time-efficient training strategy for enhancing aerobic power, given to the lower volume session required by RST when compared to other high-intensity aerobic interval training. For example, Bravo et al. [44] demonstrated similar aerobic adaptations between RST ( ∼ 10-min) and high-intensity aerobic interval training consisted of 4 sets of 4 min running at 90–95% of HR max ( ∼ 18-min), and greater improvement in RSA AT , despite the lower volume of RST ( ∼ two-fold). In our study, a volume of ∼ 2.5-min per session (without active recovery) induced greater improvements in aerobic fitness and neuromuscular components than the control group.

Therefore, the prescription of RST seems to be an interesting strategy for team sports. Our results clearly show improvements in RSA, vertical jump, and aerobic fitness. However, limited scientific research investigated if the training-induced improvements on those physical components might be applied in basketball-specific movements and competitive game performance. Future research should aim to provide data on those aspects, as well as, investigate the effect of other training methods on repeated jump capacity (i.e. repeated sprint with direction change and plyometric training). From a practical perspective, the RST lasting only a few weeks (i.e. six weeks) might be applied as a specific training method for conditioning in basketball performance-related physical fitness attributes before seasons. Physical conditioning coaches are strongly encouraged to include this strategy into the preparation of regular basketball training during pre-season, given that sprints and jump movements are the most high-intensity actions performed by players in games. Moreover, both are involved in discrimination function related to basketball success (i.e. blocks, rebounds, and field-goal shooting). Furthermore, those short-term training-specific adaptations offer to coaches and practitioners the possibility to emphasize on technical-tactical exercises during pre-season. Even with consistent and relevant results, these data are specifically for college basketball players, thus, a generalization of the results should be performed with caution. In regard to elite basketball players, the effects of RST on sprint, jump, and aerobic performance should be explored.

5. Conclusion

The RST additional to a common technique basketball training is effective for conditioning the neuromuscular quality-related abilities of short sprint speed, jump, and aerobic fitness in college basketball players during the last phase of the pre-season.